1. Field of the Invention
This invention relates in general to subsea wells, and in particular to a connector for connecting a riser to a subsea wellhead housing.
2. Description of the Prior Art
In a subsea well of the type concerned herein, a tubular wellhead is located on the sea floor. During drilling operations, a riser extends from a vessel at the surface down to the wellhead. A wellhead connector connects the lower end of the riser to the wellhead. After the riser is disconnected, a similar wellhead connector may be used to connect a subsea production tree to the wellhead. The wellhead connector has a housing which slides over the wellhead. In one type, a plurality of dogs are carried by the wellhead connector. The dogs include grooves on their interior sides. A cam ring moves the dogs inwardly into engaging contact with grooves formed on the exterior of the wellhead.
A plurality of pistons are spaced apart from each other circumferentially around the wellhead housing to move the cam ring axially between a locked and unlocked position. Because of the large cam ring cross-section and number of pistons, the connectors are large, heavy, and expensive to manufacture. Therefore, what is needed is a wellhead connector that is lighter, more efficient, and less expensive to manufacture.